Page 262 - Start Up Mathematics_8 (Non CCE)

2. Match the following polyhedrons and their nets with the areas of faces:

12
3
4 12 4
(a) (i)
3 12

5 12

2
6 10 6
(b) (ii)
2 15 10 15
6

2
16

(c) 5 (iii) 64 64 65 64

16
3

9

(d) (iv) 15 15 15
16
9 15
4
4
3. Draw a map showing the major landmarks on the way from your house to your school.

AT a Glance

1. A three-dimensional shape made up of polygons is called a polyhedron.
2. A polyhedron whose side faces are parallelograms and bases are congruent parallel polygons is called a
prism.
3. A pyramid is a polyhedron whose base is a polygon and whose side faces are triangles having a common
vertex called the apex.
4. Platonic solid are regular convex polyhedra. There are only five platonic solids namely tetrahedron,
hexahedron, octahedron, icosahedron, dodecahedron.
5. Euler’s formula: F + V = E + 2, where V, F and E stands for number of vertices, faces and edges of a
polyhedron respectively.

Review Exercises

Multiple ChoiCe Questions
1. The number of faces in a triangular prism are:
(a) 5 (b) 4 (c) 3 (d) 2
2. A point where three faces of a figure meet is known as its:
(a) angle (b) vertex (c) edge (d) none of these

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